This discussion of bilingual education in the United States begins with a review of the historical and political context in which it has evolved since the late 1800s. Policy issues and some research are examined here. It then outlines the theoretical and conceptual debate, focusing on four major theoretical frameworks used to justify bilingual education: those of linguistic interdependence; vernacular advantage; language transfer; and sociolinguistic/sociocultural theory. An overview of research concerning the effects and effectiveness of bilingual education is offered, distinguishing three periods in research focus. A number of program types or designs are identified, and the future of bilingual education is discussed briefly. (Contains 57 references.) (MSE)